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Ray Of Light [21]

3 years ago

10

Solve x2 - 8x - 9 = 0. Rewrite the equation so that it is of the form x2 + bx = c.

1 answer:

stira [4]3 years ago

7 0

X^2 - 8x-9=0
D = b^2- 4*a*c = 64- 4* (-9) = 64+36=100 =10^2
X1 = (8-10)/2 = -1
X2= (8+10)/2= 9

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An aircraft manufacturer wants to determine the best selling price for a new airplane. The company estimates that the initial co

Blizzard [7]

Answer:

$(a)$ $C(x)=500+20x-5x^{\frac{3}{4}}+0.01x^2$

$p(x)=320-7.7p$

$R(x)=(320-7.7p)p=320p-7.7p^2$

$(b)$ $x=82 \text{planes}$

$(c)$ $p=\$30.91 M\;\; \text{per plane}$

$(d)$ maximum profit $=\$ 15.90M$

Step-by-step explanation:

Given that,

The company estimates that the initial cost of designing the aeroplane and setting up the factories in which to build it will be 500 million dollars.

The additional cost of manufacturing each plane can be modelled by the function.

$m(x)=20x-5x^{\frac{3}{4}}+0.01x^2$

$(a)$ Find the cost, demand (or price), and revenue functions.

$C(x)=500+20x-5x^{\frac{3}{4}}+0.01x^2$

$p(x)=320-7.7p$

$R(x)=(320-7.7p)p=320p-7.7p^2$

$(b)$ Find the production level that maximizes profit.

$f=R(x)-C(x)$

$\Rightarrow f=320p-7.7p^2-(500+20x-5x^{\frac{3}{4}}+0.01x^2)$

$\Rightarrow df=320dp-15.4pdp-20dx+5(\frac{3}{4} )x^{\frac{-1}{4} }dx-0.02xdx$

$x=320-7.7p$

$p=\frac{320-x}{7.7}$

$\frac{dp}{dx} = \frac{-1}{7.7}$

$\frac{df}{dx}=\frac{320}{-7.7} -\frac{15.4(320-x) }{7.7(\frac{-1}{7.7} )}-20+5\frac{3}{4} x^{\frac{-1}{4}} -0.02x=0$

$\Rightarrow -41.5584+83.1169-0.2597x-20+3.75x^{\frac{-1}{4} }-0.02x=0$

$\Rightarrow 21.5585+3.75x^{\frac{-1}{4} }-0.279x=0$

$\Rightarrow x=82 \text{planes}$

$(c)$ Find the associated selling price of the aircraft that maximizes profit.

$p=\frac{320-82}{7.7}$

$\Rightarrow p=\$30.91 M\;\; \text{per plane}$

$(d)$ Find the maximum profit.

Manufacturing cost of one plane is:

$m(1)=20-5+0.01$

$=\$15.01 M$

maximum profit $=\$(30.91-15.01)M$

$=\$15.90M$

3 0

2 years ago

Evaluate the expression shown below and write your answer as a fraction in simplest form.

Amiraneli [1.4K]

Answer:

1/2

Step-by-step explanation:

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2 years ago

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Vladimir [108]

Answer:

5.5 inches

Step-by-step explanation:

1) the formula to find the area of a square is l^2= area and l=length

in this case we already know the area but not the length

so we have to find the square root of 30 as the opposite operation needs to be used to find the missing number

so

√30= 5.47

5.47 rounded= 5.5

the length of one side is 5.5 in

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3 years ago

9) Is 0 a solution to 3x + 8 = 5x + 8? Explain or show your reasoning .

alex41 [277]

Answer:

x=0, yes.

Step-by-step explanation:

3x+8=5x+8

5x-3x+8=8

2x+8=8

2x=8-8

2x=0

x=0/2

x=0

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3 years ago

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susan mountain elevation is 1530 meters. After 4 hours of climbing down to her elvationis 680 meters. What is susans avarge chan

iVinArrow [24]

Answer:

-850 is the answer

Step-by-step explanation:

8 0

3 years ago

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